The invention relates to a dispenser for distribution of measured quantities of fluid to pasty products, comprising of a storage container with axially displaceable guide pistons and a dispenser head with dispenser pump arranged on the storage container, whose pump chamber is restricted by check valves at the entry and exit as well as a discharge channel inserted after the dispenser pump with an application opening that can be sealed by a sealing element.
Various devices are known for the measured distribution of fluid to pasty products for squeezing out the product from the storage container through an application opening, which differ fundamentally with regard to the structural design and function.
A dispenser of the foregoing described type is known from EP 0 048 420 B1. The dispenser consists of a hollow cylindrical storage container with a lower open end, which is sealed by an axially displaceable guide piston. The upper end of the storage container has a top surface with an inlet valve.
A dispenser head with a dispenser pump located within is arranged on top of this cylindrical storage container, whose pump chamber is restricted by check valves at the entry and exit as well as with a mouthpiece with an application opening inserted after the dispenser pump.
In the measured discharge of the product to be dispensed, through a downward directed outer pressure on the dispenser pump, whereby the pump compresses, the outlet valve is opened and the inlet valve is closed and the product in the pump chamber is squeezed out through the application opening of the mouthpiece.
Upon the release and the subsequent relaxing and expansion of the dispenser pump, the outlet valve is closed and the inlet valve is opened. The vacuum forming through the expansion of the dispenser pump in the pump chamber now causes a suction of new product from the storage container through the inlet valve of the top surface, whereby the piston moves further in the direction towards the top surface. This operation can be repeated until the storage container is empty and the piston has contact with the top surface.
From the German registered utility model G 92 12 242.6, in which a similar dispenser is described, it is known to seal the opening of the discharge channel with a loose plug. However, with a dispenser of this type the danger exists that the loose plug sealing the discharge opening will be lost or accidentally thrown away by the user after a single use of the dispenser, so that dirt or bacteria can seep into the unsealed discharge channel and spread within the dispenser. In addition, the possibility exists that a plug that has fallen to the floor will be inserted back into the discharge channel by a careless user without being cleaned. A further disadvantage in the use of a plug consists in the fact that in the insertion of the plug a small quantity of product will be squeezed out to the side of the plug and dampen the dispenser or the hands of the user.
To eliminate these described disadvantages, in the German registered utility model G 94 19 268.5 it is proposed to arrange at the lateral opening of the discharge channel a self-activating sealing check valve as an opening valve. The opening valve consists of an elastic sealing lip ring, which sits close laterally against the cylinder jacket area of a pivot in the off position, with the pivot arranged within or in front of the discharge opening. The diameter of the pivot is greater than the opening diameter of the relaxed sealing lip ring in the application setting.